1. Technical Field
The present invention relates to the technical field of a composite image generating system, an overlaying condition determining method, an image processing apparatus, and an image processing program which overlays an image of at least one virtual object on an image of the real world, generating a composite image of the real world and the virtual object, and realizing augmented reality.
2. Background Information
A technique of overlaying an image of a virtual object on an image of the real world (or, an object which exists in a real space) to provide an image in which it looks as if the virtual object existed in the real world to augment a real world, is called “Augmented Reality” (hereinafter, referred to as “AR”). (For Example, please see Japanese patent Laid-open No. 2004-213673; Japanese patent Laid-open No. 2004-534963; Japanese patent Laid-open No. 2005-507109).
In such augmented reality, so that a position and an orientation of a virtual object (several virtual objects can be overlaid and each can have an individual position and orientation) as an overlaid image, a distance from a camera for capturing an image (a distance from a view point of viewer), and the like (hereinafter, referred to as “overlaying condition”) do not become unnatural, it is necessary that an overlaying location, a position and an orientation (attitude) of the object to be overlaid, and the like, a distance from a camera, and the like (hereinafter, simply referred to as “condition”) is exactly grasped, and an overlaying condition of an image of the virtual object is determined in correspondence with this condition.
From such point of view, in case of prior art, a technique called a marker tracking has been widely used. In such a technique, a marker (or more than one) which is a predetermined figure, and the like printed on a board, paper, and the like is located at a location, an object, and the like for which a condition needs to be grasped, a captured image is analyzed, and a position, and an orientation of marker, a distance from a camera, and the like are discriminated, so that a condition of place, object, and the like is grasped indirectly.